1. Field of the Invention
The present invention generally relates to a flanged housing member in which a flange is disposed at one end of a trunk portion. More specifically, the present invention relates to ironing process, which is a kind of cold workings, that is being used to form a flange portion on a tubular trunk portion in which the flange portion and the trunk portion are formed as a one-piece, unitary member.
2. Background Information
A vehicle power train includes a rotation torque transmitting device that often has a constant-velocity joint. The constant-velocity joint sometimes has an outer ring that is a flanged housing member having a trunk portion with a blind bore and a flange protruding outward from the closed end of the trunk portion portion. The blind bore of the trunk portion can be provided with a plurality of tracks or grooves formed in its internal surface such that a gauge guide surface is formed between the tracks or grooves.
One conventional method for forming such a flanged housing member involves first forming the internal and external surfaces of the trunk portion and then thereafter welding a flange to one end of the trunk portion to close the end of the trunk portion. However, this is disadvantageous from the aspect of cost in that two components, i.e., a flange and a trunk portion, are required to be welded together.
Also, another conventional method involves a hot-forging process in which a flanged forged material is first formed with a through-hole. Thereafter, the external surface of the flanged forged material is machined to achieve a prescribed outside diameter and to obtain a prescribed flange and other components. In this method, the tracks or grooves and the gauge guide surfaces in the internal surface are formed by broaching and performing induction hardening. Then, in this method, a cover is attached to one end of the trunk portion. In this method, however, machining and broaching require processing time, with broaching itself being costly. Thus, this manufacturing process is inferior in terms of manufacturing costs.
Another conventional method of manufacturing a flanged cylindrical member that has a through-hole is disclosed in Japanese Laid-Open Patent Application No. 02-025223 (Japanese Patent No. 2661669). In this publication, a method is disclosed in which the flanged cylindrical member is formed using a cold forming process. This cold forming process includes using a punch to finishing the internal surface of the trunk portion. In this cold forming process, the punch is inserted into the trunk portion from the opposite side of the flange, and a die is then thereafter inserted from the same direction as the punch to shape the external surface of the trunk portion.
A conventional method of manufacturing a flanged cylindrical member that has a blind bore is disclosed in Japanese Laid-Open Patent Application No. 63-273523. In this publication, a method is disclosed in which the flanged cylindrical member is formed using a cold forming process. Here, a forged workpiece is supported with its flange side facing downward. Then, a punch for finishing the interior surface is inserted inside the trunk portion, and an ironing die divided into a plurality of parts along the axial center is disposed on the external surface to shape the external surface of the workpiece by moving the punch or the ironing die in the axial direction and passing the workpiece through the interior of the die. Thus, the internal surface of the workpiece is brought into close contact with the external surface of the punch, and the internal and external surfaces of the workpiece are finished.
In view of the above, it will be apparent to those skilled in the art from this disclosure that there exists a need for an improved flanged housing member. This invention addresses this need in the art as well as other needs, which will become apparent to those skilled in the art from this disclosure.